The present invention relates to a vehicle parameter monitoring system and particularly to a tire pressure monitoring system which provides multiple displays conveniently located in a vehicle visor.
With the advent of new tire designs, tires infrequently lose tire pressure. Coupled with the inconvenience of checking tire pressure at self-service stations, which frequently charge for use of air facilities located at a remote location at such stations, the careful monitoring of tire pressure by vehicle owners and operators has become less frequent. The result is that frequently vehicles are operated with low tire pressure. This is not only potentially a safety problem with vehicles being operated with one or more tires having low pressure but also increases the cost to operate the vehicle due to lower fuel milage and increased wear on the tires. Thus, it is desirable to provide an operator with a system by which the operator can monitor the pressure of the tires of the vehicle within the vehicle itself so that, in the event the pressure in one or more tires falls below a predetermined threshold, the vehicle operator is alerted to such condition and can take corrective action by either adding air to the tires for proper inflation or having the tire or tire stem repaired, if necessary.
One such tire pressure monitor is represented by U.S. Pat. No. 5,661,651 entitled WIRELESS VEHICLE PARAMETER MONITORING SYSTEM, which issued Aug. 26, 1997, to the present assignee. This system provides for the transmission of radio frequency signals carrying information representative of tire pressure and transmitting such information to a vehicle receiver coupled to a circuit for displaying the decoded pressure indication information transmitted from each of the vehicle tires. The pressure information is then selectively available to the vehicle operator through a message center typically located in the overhead console or in the instrument panel. Although the message center can take on a number of different forms, it is desired to provide a system which is operator friendly in that it alerts the operator to the existence of a problem and subsequently allows the operator to seek additional information as to the source and nature of the problem.